IDi PFRFF.Cl SOClETll.S OF JNSECTS. 



a hook, to which he fastened a hair with a small square 

 of very thin paper at the other end ; this was exactly op- 

 posite to the aperture, at the distance of about an inch 

 irom it. As soon as the apparatus was fixed, the hair 

 with its paper pendulum began to oscillate more or less, 

 the greatest oscillations on both sides being an inch, by 

 admeasurement, from the perpendicular : if the paper 

 was moved by force to a greater distance, the vibrations 

 did not take place, and the apparatus remained at rest. 

 He then made an opening in the top of the hive, and 

 poured in some liquid honey : soon after there arose a 

 hum, the movement in the interior increased, and some 

 bees came out. The oscillations of the pendulum upon 

 this became more frequent and intense, and extended to 

 fifteen lines or an inch and a quarter from the perpendi- 

 cular ; but when the paper was removed to a greater di- 

 stance from the aperture, it remained at rest. 



Huber, at the proposal of M. de Saussure, in order 

 to ascertain whether artificial ventilators would produce 

 an analogous effect, got a mechanical friend to construct 

 for him a little mill with eighteen sails of tin. He also 

 prepared a large cylindrical vase, into which he could, 

 at an aperture in the box upon which it was fixed, in- 

 troduce a lighted taper. In one side of this box was an- 

 other aperture to represent that of a hive, but larger. 

 The ventilator was placed below, and luted at the points 

 of contact, and anemometers were suspended before the 

 aperture. The first experiment was the introduction of 

 the taper, without putting the ventilator in motion. 

 Though the capacity of the vessel was about S228 cubic 

 inches, the flame soon diminished, and went out in about 

 eight minutes, and the anemometers continued motion- 



